\[\boxed{\mathbf{838}\mathbf{.}}\]
\[1)\ f(x) = \cos\left( \frac{x}{2} - 1 \right) + e^{3x}\]
\[f^{'}(x) =\]
\[= \left( \cos\left( \frac{1}{2}x - 1 \right) \right)^{'} + \left( e^{3x} \right)^{'} =\]
\[= - \frac{1}{2}\sin\left( \frac{x}{2} - 1 \right) + 3e^{3x}\]
\[2)\ f(x) = \sin\left( \frac{x}{3} + 3 \right) + 2^{x}\]
\[f^{'}(x) =\]
\[= \left( \sin\left( \frac{1}{3}x + 3 \right) \right)^{'} + \left( 2^{x} \right)^{'} =\]
\[= \frac{1}{3}\cos\left( \frac{x}{3} + 3 \right) + 2^{x} \bullet \ln 2\]
\[3)\ f(x) = 3\cos{4x} - \frac{1}{2x}\]
\[f^{'}(x) = 3 \bullet \left( \cos{4x} \right)^{'} - \frac{1}{2} \bullet \left( \frac{1}{x} \right)^{'} =\]
\[= 3 \bullet ( - 4) \bullet \sin{4x} - \frac{1}{2} \bullet \left( - \frac{1}{x^{2}} \right) =\]
\[= - 12\sin{4x} + \frac{1}{2x^{2}}.\]